Kids' sports are intended to be recreational. To the extent that they teach self-discipline, striving for excellence, and fitness as a way of life, they are beneficial.
Psychologically forcing kids to spend excessive time in these pursuits (the kids believe they are only doing what they want to do) is abusive. While the instant comment is on girls' gymnastics, the same principle can be applied to other kid sports as well. No one under 16 years old should be participating in international (or even national) competitions.